bug#33796: 27.0.50; Use utf-8 is all our Elisp files

[Eli Zaretskii <eliz@gnu.org>]

> Cc: monnier@iro.umontreal.ca, 33796@debbugs.gnu.org
> From: Paul Eggert <eggert@cs.ucla.edu>
> Date: Thu, 20 Dec 2018 13:49:44 -0800
> 
> On 12/20/18 8:06 AM, Eli Zaretskii wrote:
> 
>  > my opinion should also count, right?
> 
> Of course, although my impression was that you weren't expressing an 
> opinion and were soliciting opinions.

Same as Stefan, actually: he asked whether there were objections.

>  > we need the opinion of people
>  > who might be actually affected by the proposed change,
> 
> I assume you mean that we need the opinion of people who would be 
> affected _negatively_.

Not necessarily.  I would actually like to hear opinions from people
who read CJK scripts who think the distinction no longer matters, not
these days.

>  > All 3 of us simply don't care,
> 
> No, actually I do care. Non-UTF-8 source files are a real annoyance for 
> me

This is a misunderstanding: by "don't care" I meant we don't care
which font is used to display a particular Unicode codepoint in the
Han area.

> I do think we should cut down on the unnecessary markup 
> in that file.

Agreed.

> The markup should be used only when it helps. Text like 
> "<x-charset><param>mule-unicode-0100-24ff</param> </x-charset>" is not 
> helping anybody; the file should just contain " " there.

There are only 2 such occurrences, so this isn't a grave problem.  I
will take a look when I have time.

> Most of the markup in that file is not necessary for proper display,
> and just gets in the way when using tools other than Emacs.

Which markup is not necessary for display, in your opinion?  I'm
surprised to hear that "most of it" is unnecessary, but maybe I'm
missing something.

>  >  . By the above reasoning, if Emacs is enhanced to interpret HTML/XML
>  >    and show typefaces instead of markup, you will see that as a
>  >    regression and complain that raw HTML files are "gibberish"?
> 
> I hope Emacs doesn't do any such thing by default.

Really?  Quite a few Emacs users think that it should, and that the
fact it doesn't is one of the significant deficiencies in Emacs, as
compared to other popular editors.

> </x-charset><x-charset><param>greek-iso8859-7</param>Greek (ελληνικά)   
> Γειά σας
> 
> It would be better to remove this particular markup, so that git etc. 
> would show this:
> 
> Greek (ελληνικά)    Γειά σας
> 
> which is what Emacs ordinarily shows.

That markup is precisely what keeps the charset properties on the
corresponding greetings.  Removing it would be losing information that
HELLO is trying to preserve.

> I don't use that menu, but I took your hint and just now 
> tried it, by selecting the abovementioned word "ελληνικά" and menuing to 
> Edit > Text Properties > Describe Properties, but all it said was 'Text 
> content at position 1530: There are text properties here: unknown 
> ("x-charset")'. This missed the point that the word's character set is 
> greek-iso8859-7

I cannot reproduce this.  That menu item invokes the command
describe-text-properties, which pops up the *Help* buffer, and the
text there says:

  Text content at position 1530:


  There are text properties here:
    charset              greek-iso8859-7

I wonder why you don't see that.  Is it possible that you are looking
at a file/buffer that was modified from its original contents?

> which is a special hack that hints to Emacs (and nobody else, I
> guess? I couldn't find documentation for this stuff even in the 
> Emacs manuals) that the text should be displayed with a Greek font 
> instead of the same Greek font that Emacs would be using anyway.

The charset property allows us to have a fontset that directs Emacs to
use specific fonts for specific character ranges.  See set-fontset-font.
I do agree that these issues are notoriously under-documented.